Dielectric nose cone antenna



March 28, 1961 o. E. KIENOW DIELECTRIC NOSE CONE ANTENNA Filed Nov. 4. 1947 IIVVE/VTOI? (MW/1L0 lf/ENOW 5 Y Uniedsme Patent 'invention relates to antenna systems, and more particularly, to microwave aritenhis." systems for airborne radio apparatus such as may .be fc-arried by vehicles adapted tomove through space ML-supersonic speeda-"ror example, guidedmissiles. a

The bodies of s'uch'v ""le" 'iriust, obviously, be streamnd it lies heietef e be a" 1 pbr'afe an ari'tennasystem in' sfieh a' enieie which wandfunction efiiciently for its own purpose and, at the same time, not interfere with said streamlining.

It is, therefore, among the objects of the present inventiop to solve the aforesaid problem, and provide a simple and easily made antenna system which will function efliciently as a radio-receiving or radiating element and not disturb the streamline of the vehicle bearing the same.

These, and other objects of the present invention, which will become more apparent as the detailed description thereof progresses, are attained, briefly, in the following manner.

The body ofthe vehicle is, as already indicated, streamlined, and the antenna system is incorporated in and extends forwardly from said body, said system itself being provided with a streamline surface which is continuous with the streamline surface of the vehicle.

The antenna system comprises a supporting member, substantiallyin the form of a frustum of a cone, which is provided with a pair of communicating axial bores of different diameters. A hollow wave guide, which is adapted to be coupled to a microwave transmitter or receiver carried in the body of the vehicle, is secured 'in the larger of said axial bores and extends rearwardly into said vehicle. A radiating element, for example, a dielectric rod, is secured in the smaller of said axial bores and extends forwardly through the nose of said vehicle. The outer extremity of said radiating element is substantially conically shaped to form a continuous surface with the surface of the supporting member. The inner extremity of said radiating element is provided with a suitably shaped, dielectric nubbin which extends into the above-mentioned wave guide properly to match said radiating element to said wave guide.

An antenna system made as aforesaid has been found efiiciently to function as a radiator or receiver of microwave energy and, at the same time, to blend unobtrusively into the over-all streamline of the vehicle equipped therewith.

In the accompanying specification there shall be described, and in the annexed drawing shown, an illustrative embodiment of the antenna system of the present invention. It is, however, to be clearly understood that the present invention is not tobe limited to the details herein shown and described for purposes of illustration only, inasmuch as changes therein may be made without the exercise of invention, and within the true spirit and scope of the claims hereto appended.

men; toineorg r 2 in said drawing, 1 t Fig. 1 is a top plan view of a vehicle, such as a guided missile, equipped with an antenna assembly made in ac esreanee fwith the present invention;

Fig. 2 is an enlarged, longitudinal sectional view taken slang line ofFig. 1; and

Fig; 3 is atra'nsvers'e' "sectional view, with the vehicle body removed, taken along line 3-4 of Fig. 2.

Referringnow more in detail to the aforesaid illustrative embodiment of the, present invention, with particular reference to the drawing illustrating the same, the numetal 16 generally designates an airborne vehicle, for example, a guided missile ofv the type intended to move through space", at'afsupersonic speed. The vehicle comprises treai'rilined body '11-, the forward end of which ntia-llyin the form of a frustum'of a cone and is a apted to receive "the substantially conically shaped antenna assembly 1215f the present invention to come' assembly 12; includes a supporting member 13 triad entertainer-metal; shaped "substantially like 'a frusnim er a 'coiie, aiidi provided with communicating anal-nines l' t-afic'l 15 of different diameters. The supporting member 13 is further provided, adjacent the base thereof, with a peripheral groove 16 receptive of the inner ends of a plurality of set screws 17 carried by the body 11 of the vehicle 10 for securing said supporting member to said body. In order to prevent relative rotational movement between said supporting member 13 and said body 11, the former is still further provided, in the face of the base thereof, with a pair of diametrically opposed slots 18 receptive of keys 19 formed on the body 11.

Threadedly engaged in the bore 15 is a disk 20 provided with a central rectangular opening in which is secured, as by silver soldering, a hollow wave guide section 21. The latter extends rearwardly into the body 11 of the vehicle 10 and carries, at its inner end, a flange 22 which, together with a similar flange 23, mounted on the outer end of a second hollow wave guide section 24 axially spaced from the section 21, form the wave guide ends of a quarter-wave cylindrical skirt 25 carried by said flange 22, to function as a radio-frequency choke coupling between'the two wave guide sections 21 and 24. The wave guide section 24 is coupled, in any suitable manner, to a radio transmitter or receiver, not shown, carried in the body 11 of the vehicle 10.

Disposed in the bore 14, and fixed therein as by cementing, is a cylindrical rod 26 made of dielectric material, such as polystyrene, said rod being provided, beyond the forward end of the supporting member 13, with a substantially conical portion 27, the outer surfaces of said conical portion 27, said supporting member 13, and the body 11 of the vehicle 10 being continuous so as not to interrupt the streamline of said vehicle 10.

The inner end of the rod 26 is recessed to receive, as by a force fit, a dielectric nubbin 28 which extends into the wave guide section 21 and which is appropriately shaped, for example, like a frustum of a cone, to provide a suitable impedance match between the rod 26, which constitutes the radiating or receiving element of the system, and the wave guide section 21.

This completes the description of the aforesaid illustrative embodiment of the present invention. It will be noted from all of the foregoing that the antenna assembly of the present invention is simple in construction, easy to fabricate and assemble, and provides a continuous surface with the vehicle bearing the same so that the streamline of said vehicle is preserved. At the same time, the assembly provides an efficient radiator or receiver for radio apparatus adapted to be airborne by speeds.

Other objects and advantages of the present invention will readily occur to those skilled in the art to which the same relates.

. What is claimed is: v

1. An antenna assembly comprising: a supporting member shaped,substantially, like a frustum of a cone, and provided with communicating axial bores; a hollow wave guide, secured in one of said bores, and extending outwardly from said supporting member coaxially therewith; a dielectric radiating element, secured in another of said bores, and having a substantially conical portion extending outwardly therefrom, in a direction opposite to that of said wave guide, to form a continuous surface with the outer surface of said supporting member; and a dielectric, impedance-matching nubbin extending outwardly from said radiating element into said wave guide. 2. An antenna assembly comprising: a supporting member shaped, substantially, like a frustum of a cone, and provided with communicating axial bores of difierent diameters; a hollow wave guide, secured in the larger of said bores, and extending outwardly from said supporting member coaxially therewith; a dielectric rod, secured in the smaller of said bores, and having a substantially conical portion extending outwardly therefrom,

in a direction opposite to that of said wave guide, to form a continuous surface with the outer surface of said supporting member; and a dielectric, impedance-matching nubbin extending outwardly from said rod into said wave guide.

References Cited in the file of this patent UNITED STATES PATENTS 2,235,139 Bruce Mar. 18, 1941 2,368,663 Kandoian Feb. 6, 1945 2,403,567 Wales July 9, 1946 2,421,085 Rylsky May 27, 1947 2,424,193 Rost et al. July 15, 1947 2,425,336 Mueller Aug. 12, 1947 2,429,640 Mieher et a1. Oct. 28, 1947 2,460,401 Southworth Feb. 1, 1949 2,497,706 Wetherill Feb. 14, 1950 FOREIGN PATENTS 91,592 Sweden Feb. 24, 1938 539,224 Great Britain Sept. 2, 1941 OTHER REFERENCES Radio Proximity Fuse Design," National Bureau of Standards Research Papers RP 1723, vol. 37, July 1946. 

